Two-way tuning of structural order in metallic glasses

Hongbo Lou,Xiaobing Zuo,Vitali B Prakapenka,Wei-Hua Wang,Jianguo Wen,Songyi Chen,Zhidan Zeng,Tao Li,Yang Ren,Fei Zhang,Hongwei Sheng,Xiehang Chen,Qiaoshi Zeng,Peng Luo,Clemens Prescher

doi:10.1038/s41467-019-14129-7

Abstract

Metallic glasses are expected to have quite tunable structures in their configuration space, without the strict constraints of a well-defined crystalline symmetry and large energy barriers separating different states in crystals. However, effectively modulating the structure of metallic glasses is rather difficult. Here, using complementary in situ synchrotron x-ray techniques, we reveal thermal-driven structural ordering in a Ce65Al10Co25 metallic glass, and a reverse disordering process via a pressure-induced rejuvenation between two states with distinct structural order characteristics. Studies on other metallic glass samples with different compositions also show similar phenomena. Our findings demonstrate the feasibility of two-way structural tuning states in terms of their dramatic ordering and disordering far beyond the nearest-neighbor shells with the combination of temperature and pressure, extending accessible states of metallic glasses to unexplored configuration spaces.

Highlights

Metallic glasses are expected to have quite tunable structures in their configuration space, without the strict constraints of a well-defined crystalline symmetry and large energy barriers separating different states in crystals
metallic glasses (MGs) are thermodynamically metastable and will naturally and rapidly crystallize into stable crystals with long-range translational symmetry when heated above their crystallization temperatures
It is worth to note that a new glass transition-like endothermic signal was observed in the regular differential scanning calorimetry (DSC) measurement of the highordering state (HOS) sample and a similar one in the reversible heat flow in the temperature modulated DSC measurement (TMDSC) (Supplementary Fig. 7a and 7b)

Summary

Introduction

Metallic glasses are expected to have quite tunable structures in their configuration space, without the strict constraints of a well-defined crystalline symmetry and large energy barriers separating different states in crystals. Using complementary in situ synchrotron x-ray techniques, we reveal thermal-driven structural ordering in a Ce65Al10Co25 metallic glass, and a reverse disordering process via a pressure-induced rejuvenation between two states with distinct structural order characteristics. Our findings demonstrate the feasibility of twoway structural tuning states in terms of their dramatic ordering and disordering far beyond the nearest-neighbor shells with the combination of temperature and pressure, extending accessible states of metallic glasses to unexplored configuration spaces. In this work, using in situ high-energy XRD and small-angle xray scattering (SAXS) techniques, we study the high-temperature behavior of a Ce65Al10Co25 MG and confirm that a notable ordering process from SRO extended to MRO occurs during heat treatment prior to its primary crystallization. The electrical conductivity is investigated for both ordering and disordering processes to demonstrate

Methods

Results

Conclusion